Crossbench anger at the prospect of Senate voting reform has bubbled over, with minor parties threatening to target the Coalition in marginal lower house seats at this year's election as pay back for changes they say will lock them out of Parliament.

Minor party threat: Family First's Bob Day and Liberal Democrat David Leyonhjelm. Photo: Andrew Meares

The 16 target seats include Deakin, Corangamite and La Trobe in Victoria - all held by Liberals with margins of 4 per cent per cent or less - and Lindsay, Banks, Macquarie and Eden-Monaro in NSW - held by Liberals with margins of 5 per cent or less.

The retaliation plan will be discussed at a forthcoming meeting of the minor party alliance, run by the so-called "preference whisperer" Glenn Druery, in early March.

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NSW senator David Leyonhjelm, leader of the Liberal Democrats, said if the Turnbull government strikes a deal with the Greens and Nick Xenophon to abolish the group voting ticket - the system that allows micro parties to magnify a small primary vote through preference deals - there would be "no future" for small parties in the Senate.

Senator Leyonhjelm said minor parties would run "as many candidates as possible" in marginal seats the government will be desperate to hold. "The aim would be to take votes away from them and, to the extent we can, direct preferences to Labor," he said.

Bob Day's Family First would likely focus on seats like Hindmarsh in South Australia where the party's preferences have been crucial to the success of Liberal candidates in the past.

Senator Day said he doesn't believe the government will go through with a deal with the Greens because it would alienate the crossbench and disenfranchise the 25 per cent of voters who backed a minor party at the last federal election.

"It doesn't make sense. It will permanently entrench the Greens with the balance of power in the senate and upset a crossbench that helped it get rid of the carbon tax, the mining tax and sort out border control," he said.

Despite some support for voting reforms within its ranks, Labor's Senate leader Penny Wong, Stephen Conroy and Sam Dastyari are convinced the changes would benefit the Coalition and prevent the ALP ever getting a future majority without relying on the support of the Greens.

On Wednesday, Senator Wong said she was concerned at the prospect of a backroom deal between the Greens and the government.

"I've been in the Senate a fair while and the thought of Bob Brown or Christine Milne doing a deal with Coalition to change the Senate voting laws would be pretty unusual. We don't want, under Senator Richard Di Natale and Lee Rhiannon, a backroom deal of which Australians know nothing other than what's been leaked out," she said.

"Let's just remember what would have happened in 2014 ... if Tony Abbott's budget had been able to pass through the Senate unamended. I don't think Australians would thank the Greens for that kind of outcome," she said.

Under the proposed reforms, suggested by Senator Xenophon and backed by the Greens, the group voting ticket would be abolished and voters able to direct preferences by choosing up to six candidates above the line.